Car amplifiers are a crucial part of a well-balanced sound system. Too little power and it can cause your speakers to distort and blow or put additional stress on your amplifier that can cause it to overheat and shut down. Too much power and you can cause damage to your speakers' cones and mechanical parts, causing them to blow as well.  Finding a good match for your speakers and subwoofers is key, here's how you do it.

Max (Peak) Vs RMS Power

Lets start by going over speakers and amplifier ratings and what they mean.

The difference between “Peak Power” and “RMS Power” is simple, so don't let it confuse you. RMS Power is a measure of the amplifier's continuous power. It's the realistic amount of power that the amplifier is rated for. It's more of an average of the wattage output over a set amount of time. Peak Power can best be described as the “peak” amount of power that the amplifier can generate or handle in a very short amount of time, a burst. It is not the amount of power the amplifier emits on a continuous basis, but more of a quick burst.

Even though the Peak Power ratings are marketed by speaker and amplifier manufacturers to catch the eyes of consumers, it is not the Peak Power, but the RMS Power that you want to use as a tool to match the right speaker with the right amplifier.

Amplifier Size and Fit

Amplifier selection might not just be all about power, size and fit might be equally important. Especially if you're trying to cram it into a tight location. Consider the physical dimensions of the amplifier and whether it will fit in your vehicle's available space. Some ams are designed specifically to be compact, while others are larger and may require custom installation in order to fit them where you want them. Ensuring that the amplifier can be securely and safely mounted in your chosen location is not something to be overlook. Taking into account factors like ventilation and access for wiring will help with long term problems like overheating. We recommend that you always measure the available space before making a purchase to avoid any installation hassles!

Wiring & Installation

Proper wiring and installation are another critical component that will impact the performance and safety of your car amplifier. Follow the manufacturer's guidelines for wiring. Every amp should come with one, which will note instructions on power, ground, and signal connections. Using the proper gauge wire to handle the amplifier's power requirements will help prevent serious damage to your vehicle, or even fire.

If you're not confident in your installation skills, you can always consider professional installation to avoid potential issues with electrical systems, overheating, or incorrect connections that could damage your amplifier or vehicle. You can also take a look at our article that details out how to install and wire an amplifier.

Multi-Channel vs Mono Channel Amplifiers

Amplifiers come in two primary configurations: multi-channel and mono-channel. Multi-channel amplifiers can power multiple speakers. Some multi-channel, like 5 channel amps, are suitable for powering both speakers and amplifiers and have a dedicated channel that's suitable for a car subwoofer's power needs. They are more versatile and allow you to fine-tune your system for different frequencies and audio components when compared to a mono channel amplifier. On the other hand, mono-channel amplifiers, also known as “monoblocks,” are dedicated to powering subwoofers. They output the frequencies that cover deep, booming bass that everyone craves in a well-rounded stereo.

Deciding between multi and mono amplifiers depends on your audio goals and the number of speakers and subwoofers in your setup. Again, multi-channel amps offer flexibility, while mono-channel amps are really specialized in delivering powerful, low-frequency bass. Choose the type that best aligns with your audio preferences and needs.

We recommend, if possible to have a dedicated channel for each speaker or subwoofer in your system. Especially standard 4 speaker + 1 subwoofer setups.

Distortion & THD

To achieve high fidelity sound, select a subwoofer amp with a wide frequency response plus low deviation. Pay attention to distortion or what manufacturers call THD or Total Harmonic Distortion. The lower the THD, the more superior the audio quality will be. Obviously, you also have to make sure all other audio components are of high quality as well like you speaker, player, and music tracks.


This measure the resistance to the current from an electric circuit. Amplifiers need speakers with a minimum of 4 ohms. When shopping for one of the best subwoofer amplifiers, opt for low impedance or low resistance.

Amplifier Classes

Amplifiers are classified into 3 classes based on their internal design: Class A, A/B, and D. Class A is rare and not popular because they have poor power consumption efficiency albeit a slightly better sound quality and A/B. The A/B is very common and easy to find, but if you want the best mono amps, you should target the D class which is high-powered subwoofer amps with an efficiency range of 80% of higher. Class D also consumes less current and is less likely to overheat. Check out our amplifier classes defined article for a more comprehensive look at the various amplifier classes

Signal-To-Noise Ratio

Decibels is the unit used to measure Signal-to-Noise ratio. This measurement describes the distance between the audio noise floor and the wanted signal. You should target a higher ratio because it indicates less distortion and noise.

CEA 2006

This is the latest standard used to compare amps. It replaced the old EIA 517B, although some companies still use the old standard. The CEA 2006 logo is a stamp of approval that the product has adhered to the industry standards, and the product specification has been proven to be valid and true. The two basic features checked using the CEA 2006 standards are output power and Signal-to-Noise ratio.

Matching an Amplifier With a Speaker

Now that you know an amplifier's RMS Power rating is a more accurate measurement of the power output, you can use it as a tool to correctly match it to the speaker(s) and subwoofers you want to use. You will want to match the RMS rating of the amplifier to the RMS rating of the speaker or subwoofer. The closer these two numbers are to eachother, the better match you have. For example, if an amplifier has an output of 100 watts x 4 channels RMS, this will mean that you want a speaker that has a 100 watt RMS rating (or in this case 4 speakers with a 100 watt rating). Same goes with a subwoofer. Read up on our article about how to pair an amplifier with speakers and subwoofers for more information!